"I have lost, by a spontaneous _Diarrhœa_, two pounds in twenty-four hours; and Mr. Rye lost twice that quantity in the same time."--_On the Food and Discharges of Human Bodies_, by B. ROBINSON, p. 84. "Most _Chronic Diseases_--arise from too much _Food_ and too little _Exercise_,--both of which lessen the weight of the Heart and the quantity of Blood;--the first by causing fatness; the second by a diminution of the blood's motion. "Hence, when the LIVER is grown too large by Intemperance and Inactivity, it may be lessened and brought to a healthful magnitude by Temperance and Exercise.--It may be emptied other ways by art; but nothing can prevent its filling again, and consequently secure good and constant Health--but an exact Diet and Exercise. Purging and Vomiting may lessen the Liver, and reduce it to its just magnitude;--but these evacuations cannot prevent its increasing again, so long as persons live too fully, and use too little exercise--and can only be done by lessening the Food and increasing the Exercise." "Much sleep, much food, and little exercise, are the principal things which make animals grow fat. If the Body, on account of Age or other Infirmities, cannot use sufficient Exercise, and takes much the same quantity of Sleep, its weight must be lessened by lessening the Food, which may be done by lessening the Drink, without making any change in the Meat; as I have proved myself by experience."--p. 90. On this subject, see also--Dr. STARK on _Diet_, and SANCTORIUS' _Medecina Statica_. Dr. HEMING on _Corpulency_.--Mr. WADD on _Corpulency_.--Dr. ARBUTHNOT on _Aliment_. SLEEP. "When tired with vain rotations of the Day, Sleep winds us up for the succeeding dawn." YOUNG. Health may be as much injured by interrupted and _insufficient Sleep_, as by luxurious indulgence. Valetudinarians who regularly retire to rest, and arise at certain hours, are unable, without injurious violence to their feelings--to resist the inclination to do so. "Pliant Nature more or less demands As Custom forms her; and _all sudden change She hates_, of Habit even from _bad_ to _good_. If faults in Life--or new emergencies From Habits[24] urge you by _long time_ confirm'd, Slow must the change arrive, and stage by stage, Slow as the stealing progress of the Year." ARMSTRONG'S _Art of Preserving Health_. How important it is, then, to cultivate good and convenient Habits:--_Custom_ will soon render the most rigid rules, not only easy, but agreeable.-- "The Strong, by bad habits, grow weaker, we know; And by good ones, the Weak will grow stronger also." The Debilitated require much more rest than the Robust:--nothing is so restorative to the nerves, as sound, and uninterrupted Sleep, which is the chief source of both Bodily and Mental Strength. The Studious need a full portion of Sleep, which seems to be as necessary nutriment to the Brain, as Food is to the Stomach.